Water has been known for millennia for its fire retardant and extinguishing properties and remains the predominate material used to extinguish or prevent certain types of fires. Water has a high heat capacity and high heat of vaporization, such that when water is sprayed onto a fire, the water that reaches the flames absorbs the heat of the fire and cools the article to below its combustion temperature. Water also deprives the fire of oxygen. Often the heat of the fire turns a portion of water into vapor before it can reach the flames. Since water vapor is heavier than air it displaces the oxygen surrounding the fire, thereby suffocating the fire.
A significant disadvantage often encountered using water to extinguish a fire is that much of the water ends up being wasted. Most of the water applied directly to the fire is turned into steam and evaporates before it can reach the base of the fire, where the combustible fuel for the fire resides. As much as 90 to 95% of the water that does manage to reach the flames simply runs off into the ground without remaining on the structure that is burning. Moreover, considerable effort must be made to continuously soak objects with water near the fire that could ignite. The evaporated and runoff water must be constantly replaced.
U.S. Pat. No. 5,989,446 discloses a water additive for use in fire extinguishing and prevention. The additive comprises a cross-linked water-swellable polymer in a water/oil emulsion that is produced by an inverse phase polymerization reaction. The polymer particles are dispersed in an oil emulsion wherein the polymer particles are contained within discrete water “droplets” within the oil. With the help of an emulsifier, the water “droplets” are dispersed relatively evenly throughout the water/oil emulsion. This allows the additive to be introduced to the water supply in a liquid form, such that it can be easily educted with standard firefighting equipment. However, it has been observed that when this additive is placed in fire extinguishers which utilize a container of water, the mixture requires agitation every 15 days to prevent the polymer from settling out. Another problem with this additive is that it takes approximately 3-4 hours to “cure” such that it is able to absorb a sufficient amount of water and attain the viscosity necessary to adhere to vertical and horizontal surfaces for firefight purposes. Also, if the additive/water mixture is not completely flushed from a hose or nozzle after use, it will harden upon drying out and render the hose or nozzle useless.
U.S. Pat. No. 7,090,029 discloses a method and apparatus for dropping fire retardant from an aircraft. A firefighting bomblet includes a container having rigid supportive walls that together define a faceted-sphere shape. The bomblet can further include a weak seam formed in one of the walls, the weak seam being adapted to be more easily ruptured than the remainder of the walls. Water and water based fire retardants are ideal for use with the bomblet.
U.S. Published Patent Application 2006/0278412 discloses a vehicle having a tire fire suppression system. The fire suppression system includes a container of fire suppressant and at least one temperature sensor in close proximity to at least one of the tires. At least one nozzle is positioned to direct the suppressant to the tire. An actuator connects the container to the nozzle for the suppressant to be dispersed from the nozzle in response to activation of the sensor. In the preferred embodiment, the cylinder contains from 5 to 25 pounds of dry chemical fire suppressant material.
U.S. Pat. No. 5,762,145 discloses a panel mounted on the exterior surface of a vehicle fuel tank. The panel is either channeled or unchanneled with extinguishant sealed therein. When the vehicle is impacted in an accident, the resultant impact deforms the fuel tank and the panel is also ruptured and releases the extinguishant. This is intended to extinguish fires or inert against potential fires in the vicinity of the fuel tank.
U.S. Pat. No. 6,915,861 discloses a system for packaging fire suppressing material. An outer membrane is configured to support and release a fire suppression material when impacted by a ballistic or incendiary round. An inner membrane is configured is configured to support and release the fire suppressant material when impacted by a ballistic or incendiary round and the inner membrane and the outer membrane is connected to form at least one cell holding the fire suppression material. The inner and outer membranes suitably form a bubble pack filled with a fire suppression powder. Further, the inner and outer membranes may be combined with a lightweight honeycomb panel to form a lightweight and simple system to support fuel tanks.
Sometimes, water must be supplied to remote locations, such as during a forest fire, often exhausting considerable physical and monetary expense. Therefore, it imperative that the fire extinguishing properties of water be optimized to reduce the amount time, effort, and cost associated with fighting fires in remote locations.
Thus, what is lacking in the art is an ability to increase the effectiveness of water for fire fighting.